Pacific Northwest National Laboratory

About: Pacific Northwest National Laboratory is a facility organization based out in Richland, Washington, United States. It is known for research contribution in the topics: Catalysis & Aerosol. The organization has 11581 authors who have published 27934 publications receiving 1120489 citations. The organization is also known as: PNL & PNNL.

Analytic Considerations and Design Basis for the IEEE Distribution Test Feeders

Abstract: For nearly 20 years, the Test Feeder Working Group of the Distribution System Analysis Subcommittee has been developing openly available distribution test feeders for use by researchers. The purpose of these test feeders is to provide models of distribution systems that reflect the wide diversity in design and their various analytic challenges. Because of their utility and accessibility, the test feeders have been used for a wide range of research, some of which has been outside the original scope of intended uses. This paper provides an overview of the existing distribution feeder models and clarifies the specific analytic challenges that they were originally designed to examine. Additionally, this paper will provide guidance on which feeders are best suited for various types of analysis. The purpose of this paper is to provide the original intent of the Working Group and to provide the information necessary so that researchers may make an informed decision on which of the test feeders are most appropriate for their work.

Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance

Abstract: In the hierarchy of cellular targets damaged by ionizing radiation (IR), classical models of radiation toxicity place DNA at the top. Yet, many prokaryotes are killed by doses of IR that cause little DNA damage. Here we have probed the nature of Mn-facilitated IR resistance in Deinococcus radiodurans, which together with other extremely IR-resistant bacteria have high intracellular Mn/Fe concentration ratios compared to IR-sensitive bacteria. For in vitro and in vivo irradiation, we demonstrate a mechanistic link between Mn(II) ions and protection of proteins from oxidative modifications that introduce carbonyl groups. Conditions that inhibited Mn accumulation or Mn redox cycling rendered D. radiodurans radiation sensitive and highly susceptible to protein oxidation. X-ray fluorescence microprobe analysis showed that Mn is globally distributed in D. radiodurans, but Fe is sequestered in a region between dividing cells. For a group of phylogenetically diverse IR-resistant and IR-sensitive wild-type bacteria, our findings support the idea that the degree of resistance is determined by the level of oxidative protein damage caused during irradiation. We present the case that protein, rather than DNA, is the principal target of the biological action of IR in sensitive bacteria, and extreme resistance in Mn-accumulating bacteria is based on protein protection.

Engineering void space in organic van der Waals crystals: calixarenes lead the way

Abstract: Seemingly non-porous organic solids have the ability for guest transport and have also been shown to absorb gases, including hydrogen, methane and acetylene, to varied extents. These materials also show potential for gas separation technology, display remarkable water transport through hydrophobic crystals, and clearly show that molecules within crystals are capable of cooperating with guests as they move through non-porous environments. This work is presented within a broader topic which also encompasses crystal engineering and (microporous) metal-organic frameworks (MOF's).

Flexible (Breathing) Interpenetrated Metal−Organic Frameworks for CO2 Separation Applications

Abstract: A breathing 2-fold interpenetrated microporous metal-organic framework was synthesized with a flexible tetrahedral organic linker and Zn(2) clusters that sorb CO(2) preferably over N(2) and H(2).